Process for sealing collapsible tubes



Jan. 16, 1940. M HALLEAD 2,187,516

PROCESS FOR SEALING COLLAPSIBLE TUBES Filed June 50, 1936 2 Sheets-Sheet l -EIG3 1 BY ATTORNEYS Jan. 16, 1940. M HALLEAD v 2,187,516

PROCESS FOR SEALING coLLAPsIBLE TUBES Filed June 30, 1936 2 Sheets-Sheet 2 INVENTOR. /VE/e v/L HAL/ E40.

BY M f/Mk ATTORNEYS.

Patented Jan.' is, 1940 UNITED STATES PATENT kol-Flclsz PROCESS FOB SEALIN TUB G COLLAPSIBLE ES Application June 30, 1936, Serial No. 88.185

7 Claims.

My invention relates to the sealing of collapsible tubes or like containers and is a departure from the methods and machines set forth in the co-pending application in the name of Paul 5 R. Fechheimer, Serial No. 710,824, flied February 12, 1934, now Patent No. 2,102,840, issued December 21, 1937, and in the co-pending application of Paul R. Fechheimer and Mervil Hallead, Serial No. 88,186, filed June 30, 1936, now Patent No. 2,141,241, issued December 27, 1938. The

fundamental object of my invention is the provision of a method and means for obtaining an improved Weld, and in particular a constructionally neater though positive closure, and this and l5 the other objects of my invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications I accomplish by that certain construction and arrangement of partsand in that process of which I shall now describe an exemplary embodiment.

Reference is now made to the drawings wherein Fig. 1 is a side elevation of a sealing assembly. Fig. 2 is a top plan View thereof. g5 Fig. 3 is a sectional view taken along the lines 3-3 oi' Fig. l.. Y

Figs. 4 to 7 inclusive show various stages in the operation of the sealing mechanism.

` Fig. 8 shows an electrically operated sealing 3 element,

. Fig. 9 is a perspective view oi the sealed end of a collapsible tube. y

Briefly in the practice o! my invention I clamp the end of a collapsible tube, the end being pinched together or fish-tailed between holding members. Next I bring down upon the end of the tubea heating element which fuses the metal of the end of the tube. Next two molding members are brought in from the sides against the a softened metal, consolidating the Weld and giving a sealed tube characterized by a neat bead at the sealed end. All of these steps can be carried on by automatic machinery in rapid succes-A sion and I shall herein describe an exemplary 45 embodiment of such machinery, it being understood that modifications can be made therein without departing from my invention.

Ordinarily, though not necessarily, the sealing of' the tubes will be carried on in connection with 50 the operation of filling them, and the lling and sealing mechanisms may form part oi the same machine. After the tubes are filled, the ends thereof will be pinched or fish-tailed, and I have shown mechanism for this purpose as a part of u my disclosure herein. In the practice of the procless herein set forth it is quite essential that the ends of the tubes to be sealed be substantially of the same height and come substantially the same distance'above the clamping-jaws in the sealing unit. While it is not necessary in all instances 5 to do this, I have found it commercially advisable to shear the ends of the tubes after pinching them, and to this end I have shown an appropriate unit operating in timed sequence with the other 'portions of my-mechanism. 10

Coming now to a detailed description of my exemplary embodiment, I have shown in Figures 1 and 2 a machine portion comprising a conveyor I having at intervals holders 2 for collapsible tubes indicated at 4. The construction of the l5 frame of the machine may be any desired, and

has not been illustrated, excepting for a bed plate 5, on or in which the conveyor moves. A divided sub-base or support 6 for the various units may be mounted above the bed plate by 20 means of posts l. The sub-base is divided to permit the upper portions of the tubes to project through it. On the sub-base are mounted the pinching, shearing, and sealing units in the order named, though the number of these units, and the number of assemblies of them per machine may be multiplied at will, as will be obvious. The two sections of the sub-base 6 will be separated at the entering end of the device suiiciently to accept the body of an uncollapsed tube as shown at 8 in Figure 2. Beyond the pinching unit the spacing between the sub-base sections may be narrowed down as shown so as to accept only the pinched ends of the tubes.

The pinching unit comprises a pair of plates 9 and I0, slidably mounted on the sub-base sections by means of bracket members il and I2 or otherwise as desired. These plates have turnedup abutment portions I3 and I4 the function of which is to pinch or iish-tail the tube ends when the plates are brought together. The operation of the pinching plates is most conveniently accomplished by providing each plate with a spring I5 or I6 operating against abutments I'l or I8 on the sub-base, and of suillcient strength to cause the plates to pinch the tube ends. The plates are then held apart or allowed to come together through the action of cam members presently to be described, upon arms I 9 and 20 attached to the plates.

All of theunits mounted on the sub-base have parts which are to be brought together against the tube enda'and it is convenient to provide for all of the units and common operating means. This means comprises a shaft 2| Journaled in I5 y of the bevel gear arrangement 25, and this shaft 2 suitable brackets 22 and 23 near the ends of the sub-base. The shaft may be connected to another shaft 24 at right angles thereto by means .a tube between the plates 9 and I0, the cams permit the plates to come together, pinching the tube as indicated at 30.

The shearing unit comprises an anvil plate 3| and a shear 32, which may similarly be slidably mounted in brackets on the sub-base, and which may similarly also be spring actuated as at 33 and 34. Preferably a clamping plate 35 is mounted on the under side of the shear plate 32, slidably, and held thereto by bolts 36, engaging in slots in the plate y35. The plate 35 will be urged forwardlyY of the shear blade by 'means of a spring connecting it with the shear blade underneath, and therefore not shown in the drawings. The shearing mechanism has actuating arms 31 and 38 which engage cams 39 and 40 on the shaft 2|. In operation the plate portions 3| and 35 come together against the pinched or fish-tailed end of the tube which projects slightly therebeyond. Immediately thereafter the shear plate 32 with its knife edge slides over the plates 35 and 3| suiiiciently to shear off the projecting end of the tube.

The tube then moves on to a sealing device, a cross section of which is clearly shown in Fig. 3. The sealing device comprises a pair of mold plates 4| and 42, slidably mounted in studs or the like 43, on the sub-base 6. The plates have abutments 44 and 45 between which and abutments 46 and 41 on the sub-base, there are compression springs 48 and 49. The plates thus are adapted to operate in the same way as the platesof the pinchn ing and shearing mechanisms. Here, as in those mechanisms, I have found it preferable to thread bolts 50 and 5| into the abutments on the plates so that the heads of these bolts will impinge ever, the plates 4l and 42 just described, are

molding members adapted to come against the end of the tube when the metal therein is molten, to consolidate the weld and to form a bead therein. As a consequence of this, these metal plates are provided with mold faces indicated at 56. It is desired to clamp the tube ends at the sealing station before these mold members come in contact with them. A suitable construction for this is shown in Fig. 3, where a plate of hard and preferably insulating substance 51 is shown attached by a screw 58 to one of the sub-base sections. This is a stationary clamping member. A movable clamping member 59 may be slidably attached as by means of screws 69, to the plate 4|, and urged forwardly of said plate by means of a compression spring 6| operating against abutment means 62 on the plate 4|.

While I have shown the plate 51 attached to the sub-base, it can if desired, be mounted on the plate 42 in a way similar to the mounting of the plate 59 on the plate 4|.

In the construction shown, it is desirable to clamp the tube end between the insulating blocks 51 and 59 as a first step in the welding procedure, afterward fusing the metal and then bringing the mold face 56 of the plates 4| and 42 against the fused metal. Consequently provision is made for two components of motion in the plate 4|. The rst component is suiiicient only to permit the plate 59 to clamp the tube against the plate 51. The second component, together with a simultaneously occurring motion of the plate 42, brings the mold face against the fused metal. The cam.55 is therefore appropriately shaped Yto accomplish this dual motion in the cycle.

A fusing means is provided and preferably 20 comprises an electrical heating element 63 of tubular shape, and comprising as shown in Fig. 8, a resistance heater 64. The heating element 63 is mounted on suitable supporting means inof these arms and adjustable by means of a bolt 6|. The spring tends to urge the heating elementy and its mounting means upwardly. One or more cams 12 mounted on the shaft 2| and bearing against suitable abutments on the mounting means 65 for the heating element, serve to bring the heating element down against the work in timed relationship.

The various steps of the sealing procedure are indicated in Figs. 4 to 1 inclusive. In Fig. 4 the pinched and sheared tube end has been brought between the insulating plates 51 and 59.' The plates 42 and 4| are in interspaced relationship and the heating element 63 does not contact the work. As a next step, and automatic consequence of the operation of the cams, the plate 4| is moved to the left in Fig.`5, sufficiently to to allow the plate 59 to clamp the tube end against the plate 51. The tube end is now held in position for welding.

As a next step, the condition shownln Fig. 6 is arrived at. 'I'he tube end is seal clamped between the insulative members 51 and 59 and the heating element 63, has been brought down against the tube end fusing the metal as at 13. The plates 51 and 59 not only serve to position the tube end but also by their insulative character serve to prevent spread of theffusion' oi the metal. Thus the fused portion of the metal lies substantially wholly above the tops of the plates 51 and 59. A material which I have found entirely suitable for the plates 51 and 59, is a hard, dense, electrically insulatve material obtainable on the open market and known as Transita, having comparatively high heat insulative properties. The final stage of the welding operation is illustrated in Fig. 7. The plates 4| and 42 have been brought together so that their mold faces 56 contact the softened body of metal 13, contact the weld and form a neat bead therein. I have found it advisable to bring the plates 4| and 42 together with some little force to achieve the desired contacting action, especially if, as is usual, the heating element 63 is raised slightly just before the plates 4| and 42 are brought together. However it is possible and within the scope of my invention, to raise the heating element Il, soon after the molding plates have been brought together. Y

The resulta'ntsealed tube is shown in Fig. 9,

as 'having a pinched or fish-tailed end 14, and a 5 neat bead 13a molded from the softened metal 13 as shown in Fig." 6.

Modifications may be made in my invention without departing from the spirit thereof.

Having thus described my invention, what LAIi claim as new and desire to secure by Letters Patent is:

1. A process of sealing collapsible tubes which comprises as sequential steps, pinching a tube end to bring. wall portions into juxtaposition, shearing said tube end to bring said wall portions to a given height, clamping said wall portions between insulating material so that they project therebeyond, softening the projecting wall portions by means of a heated member, applying molding pressure theretoy by means of molding members, and cooling the softened metal.

2. A process of sealing collapsible metal tubes by welding or fusion. which comprises bringing the end wall portions of said tubes into juxtaposed position and clamping said portions between heat insulative clamping members so that portions of said walls project therebeyond, melting the said projecting portions, and thereafter while said portions are in molten condition, bringing there- 80 against from each side, molding members having high heat conductivity, whereby the molten metal is immediately chilled and hardened.

3. A process as set forth in claim 2 wherein the fusion of said projecting portions is accoma6 plished by means simultaneously effective along the line of said projecting portions.

4. A process of sealing collapsible metal tubes by welding or fusion, which comprises bringing end wall portions of said tubes into juxtaposition,

40 trimming said wall portions whereby to expose lAfreshly cut metal surfaces thereat. and immediately thereafter sealing said wall portions together by contacting said cut surfaces with a tool for applying heat to fuse the metal thereof.

5. A process of sealing collapsible metal tubes by welding or fusion, which comprises bringing 5 end wall portions of said tubes into juxtaposition, clamping the juxtaposed walls with portions extending beyond the clamp, shearing off said projecting portions, again clamping said walls with a portion extending beyond the clamp, using for 10 this purpose clamping means of insulative substance, and fusing said end wall portions together by applyingsufllcient heat to melt the metal thereof, and immediately thereafter bringing against the melted portions of said walls heat conductive 15 molding means whereby to seal said portions.

6. A process of sealing collapsible tubes by welding or fusion, which comprises bringing end wall portions of said tubes into juxtaposition, clamping the juxtaposed walls with portions ex- 20 tending beyond the clamp, shearing off said projecting portionswhereby to expose freshly cut metal surfaces, immediately thereafter again clamping said walls with a portion extending beyond the clamp, using for this purpose clamp- 25 ing means of insulative substance, and immediately fusing said end wall portions together by means of a tool for applying sufficient heat to melt the metal thereof, said tool being brought into contact with said freshly cut metal surfaces.

7. A process of sealing collapsible tubes by welding or fusion, which comprises bringing end wall portions of said tubes into juxtaposition, trimming said end wall portions so as to expose freshly cut metal ends for welding and so as to. enforce close contact between said ends, and immediately thereafter fusing said ends together by contacting said ends with a means for applying a fusing heat thereto.

MERVIL HALLEAD. 

